• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.20-24
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• 2002

We have from water samples of Kwalim, Dochang, and Mulwang reservoirs in Kyonggi-Do, where cyanobacteria blooming occurred. Isolated microbes which have lytic activity for cyanobacteria. Water samples were smeared on the Anabaena cylindrica lawn and incubated in light chamber at $28^\circ{C}$, under 3000 lux for 13 days. A fungus having cyanobacterial lytic activity was isolated from the samples of Dochang reservoir. The isolate was identified as Cryptococcus laurentii by Vitek system. From the culture of the isolate, four major extracellular protein bands (29, 35.2, 40.9, 51.1 kDa) have been detected and the 29 kDa protein band was more thickly appeared in the culture with cyanobacteria.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1403-1412
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• 2013

Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with $H_2SO_4$. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant ${\beta}$-glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% $H_2SO_4$ for 30 min at $150^{\circ}C$. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good ${\beta}$-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.108-112
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• 2016

This study focused on the isolation of wild yeasts from the soils of an herb park in Seoul, Korea, and characterization of unrecorded yeasts. Fifteen yeast strains of nine species were isolated and identified. Among them, strains of the Cryptococcus genus, such as Cryptococcus laurentii (2 strains), Cryptococcus saitoi (two strains), Cryptococcus podzolicus (2 strains), and Cryptococcus sp. (2 strains) were dominant. Candida boleticola SU14-2, Candida novakii SU6-2 and Cryptococcus podzolicus SU18-3 were also screened as newly recorded yeasts in Korea. Candida novakii SU6-2 formed ascospores and a pseudomycelium, and Candida boleticola SU14-2 grew well in the 5% NaCl-containing yeast extract-peptone-dextrose medium.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.875-880
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• 2000

The production of glucoamylase and exopolygalacturonase from Cryptococcus laurentii Y-23 were investigated with the inducible substrates and mineral salts. Soluble starch induced only glucoamylase wherease pectin induced exopolygalacturonase as well as glucoamylase, and glucose did not induce glucoamylase whereas pectic acid induced a little amount of exopolygalacturonase. At the productions of two enzymes by inducible substrates for the 5 day-cultivation, the yeasts started log phase around 12 hours and mostly reached stationary phase around 36 hours. The best productivity of glucoamylase was observed with addition of soluble starch in the cultivation for 72 to 86 hours, and the high productivity of exopolygalacturonase was done by addition of both pectin and soluble starch in the cultivation for more than 72 hours. Without ammonium sulfate in the medium, however, cultural pH was so increased gradually that production of both enzymes were decreased and delayed as well. $Mn^{2+}$ increased both productivities of glucoamylase and exopolygalacturonase with 21% and 18%, respectively.

• The Korean Journal of Mycology
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• v.42 no.1
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• pp.28-33
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• 2014

Various yeasts from wild flowers of Ulleungdo in Gyeongsangbuk-do and Yokjido in Gyeongsangnam-do, Korea were isolated and identified by comparison of nucleotide sequences for PCR-amplified D1/D2 region of 26S rDNA using BLAST. Forty eight yeast strains of twenty two species and sixty yeast strains of twenty five species were isolated from wild flowers of Ulleungdo and Yokjido, respectively. Only seven species were overlapped from the two different islands areas: Cryptococcus albidus, Cryptococcus laurentii, Metschnikowia reukafii, Pichia scolyti, Rhodotorula glutinis, Rhodotorula graminis and Rhodotorula mucilaginosa. Among forty species from two different islands, other thirty three species were restricted to specific collection site suggesting that each area has distinctive yeast flora.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.27-36
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• 1996

The aim of the present research program was to identify and develop strains of actinomycetes producing antifungal antibiotics which inhibit cell wall biosynthesis. 860 strains of Actinomycetes were isolated from various soil samples. Three isolates, EMS4, EMP22, and L234 were selected as the strains producing antifungal antibiotics inducing abnormal morphology against Penicillium cyclopium, Cryptococcus laurentii, and Aspergillus flavus, respectively. Taxonomic unit characters of the strains were tested and the data were analyzed numerically using TAXON program. EMS4, EMP22, and L234 were indentified to be a member of Streptomyces lavendulae, Streptomyces willmorei, and Streptomyces aburaviensis, respectively.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.30-30
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• 2014

We isolated various yeasts from wild flowers in main islands, Jejudo, Ulleungdo and Yokjido of Korea and their yeasts were identified by comparison of their PCR-amplified D1/D2 regions of 26S rDNA using the BLAST database. Thirty two yeast strains of fourteen species were isolated from wild flowers of Jejudo. Forty eight yeast strains of twenty two species were isolated and identified from wild flowers of Ulleungdo, Korea. Sixty yeast strains belonged to twenty five species were isolated identified from wild flowers of Yokjido in Tongyeong, Korea. Only Metschnikowia reukaufii was overlapped from the three different islands areas. Two species overlapped from Jejudo and Ulleungdo: Pichia guilliermondii, Metschnikowia reukaufii. Seven species were overlapped from Ulleungdo and Yokjido: Cryptococcus albidus, Cryptococcus laurentii, Metschnikowia reukafii, Pichia scolyti, Rhodotorula glutinis, Rhodotorula graminis and Rhodotorula mucilaginosa. Four species were overlapped from Jejudo and Yokjido: Candida sp. Cryptococcus aureus, Metschnikowia reukafii and Pseudozyma sp.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1177-1179
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• 2015

A new approach to obtain broadly cross-reactive antisera against important yeast pathogens by intensive hyperimmunization with polysaccharide-protein conjugates is described here. Surface mannan of Candida albicans and capsular galactoglucoxylomannan of Cryptococcus laurentii were isolated and chemically linked to human serum albumin. Antisera elicited by a 7-week vigorous immunization of rabbits with the conjugates showed effective cross-reactive growth inhibition of different representatives of Candida spp. as well as Cryptococcus spp. IgG antibodies are evidenced as the effective component of the antisera.

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.73-76
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• 1993

227 red yeast strains were isolated from air (60 isolates), plant flowers (45 isolates), soil (40 isolates), water (37 isolates) and dairy products (45 isolates). On the basis of 33 different physiological and morphological properties, the isolated strains were assigned to 6 species belonging to 4 genera. Rhodotorula mucilaginosa and Cryptococcus albidus were the most dominant species among red yeasts of the air, plant flowers, water and dairy products, whereas Cryptococcus albidus and Rhodotorula glutinis were prevailed in soil. Cryptococcus laurentii was represented by considerable number of strains, whereas the other spesies were of low occurrence. Noteworthy was the isolation of 2 different groups of isolates belonging to Rhodotorula glutinis. These groups were differentiated from each other on the basis of rhamnose, cellobiose and arabinitol assimilation and growth at $37^{\circ}C$. Systematic position of Rhodotorula glutinis was discussed.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.9-18
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• 1980

During an extensive screening tests of yeasts for their RNA formation, it was found that Cryptococcus laurentii had especially high RNA content and high dry cell weight, when hydrolyzate of sliced and dried sweet potatoes was used as a carbon source. Growth conditions of this strain were examined, and the most desirable results were obtained at 48 hours of cultivation on a reciprocal shaker at 3$0^{\circ}C$ with initial pH 6.0. Under the above conditions, the RNA content and yield of dry cells were investigated using various media compositions. Ammonium sulfate 0.40%, peptone 0.6 ％, and yeast extract 0.4% were appeared to be favorable as a nitrogen sources. The optimum concentrations of K $H_2$P $O_4$, M $n^{++}$, C $O^{++}$ were 0.05 ％, 0.1 ％, and 0.001 ％, respectively. Ca-pantothenate, 400$\mu\textrm{g}$/$m\ell$, showed relatively favorable effects as a growth factor. The maximum RNA content obtained in this study was 16.8 ％ of the total dry cell weight.t.t.